Degree of calcification and cyst activity in hepatic cystic echinococcosis in humans.

To evaluate the relationship between cyst activity and calcification degree in cystic echinococcosis (CE) in humans, 99 hepatic cysts at successive stages of involution, surgically excised from 72 Sardinian patients, have been analyzed. Cysts were classified into 4 groups according to calcification extent: CALC 0 (no calcification); CALC 1 (scattered punctate calcifications); CALC 2 (large coarse segmental/partial calcifications); CALC 3 (complete or nearly complete circumferential ring of calcification up to thick wall of osseous consistency/calcified content of cyst). In addition the possible correlation with antibody response has been explored analyzing IgG1, IgG4 and IgE produced against somatic PSCAg. Results showed that calcification is not restricted to the inactive WHO cyst types CE4 and CE5, but occurs to a varying extent in all morphotypes of metacestode, from active classic unilocular or multivesicular cysts to the more complicated and highly degenerate stages, where cyst wall appears massively calcified. Prevalence of calcification increases with progression of cyst degenerative process, but is not synonymous with parasite inactivity and can be misleading as signs of calcification may coexist with still metabolically active cysts. On the contrary, detection of entirely firmly solidified content seems a reliable indication of cyst inactivity. IgG4 is the dominant isotype associated particularly with the evolutive phase. Positive rates and OD levels, higher in active vs inactive stages, are stable or increase slightly in weakly and moderately calcified cysts (CALC 1/CALC 2), compared to non-calcified ones (CALC 0), strongly decreasing in highly calcified forms (CALC 3). In conclusion, evaluation of calcification extent may be pertinent for staging CE, and immunological tests, particularly for IgG4, and IgE may help to better define cyst activity.

A study of morphological aspects of cystic echinococcosis in sheep in Sardinia.

We have investigated the morphological and structural aspects of hydatid cysts recovered from sheep raised in southern Sardinia during two surveys conducted over the 20 years since the last control attempt at the end of the 1980s. In the first study carried out during 1995-1997, a few years after the last control attempt, a total of 10,334 cysts were examined, recovered from 1029 infected sheep out of a total of 1375 inspected (prevalence 74.84%). In the second survey, conducted ten years later during the period 2005-2010 in the absence of specific control measures, a total of 6249 cysts were recovered from 916 parasitized sheep out of the 1414 examined (prevalence 64.78%). Cysts were grouped into 5 different types: "Unilocular", "Multisepted", "Calcified", "Caseous", "Hyperlaminated". Unilocular: fertile, consist of a single fluid-filled cavity; multisepted: generally sterile, fluid filled, with cavity divided into spheroidal chambers (3-dozen); calcified: sterile, small, with internal chambers almost virtual due to the thickening of internal septa; caseous: sterile, the cavity filled with a thick yellowish matrix; hyperlaminated: sterile, with a virtual cavity filled with extensively folded and overlapping sheets of hyperproduced laminated tissue. A thorough knowledge and the precise characterization of each type of lesion, making it possible to establish detailed parameters for cyst classification, appears very useful for the harmonization of data collection. From a surveillance and control perspective it is proposed that, in addition to other relevant epidemiological information, data from meat inspection be further improved, including morpho-functional indications about cyst type.

Cystic echinococcosis in sheep in Sardinia. Changing pattern and present status.

The epidemiological status of cystic echinococcosis (CE) in sheep in Sardinia over the 20 years since the last control attempt at the end of the 1980s has been assessed, comparing the results of two surveys carried out in abattoirs in southern Sardinia. In the first, conducted in 1995-1997 (5-7 years after the last control effort), CE prevalence of about 75% was observed in the 1375 sheep sampled, with intensity of 10.0 and mean abundance of 7.5. The most affected organ was the liver, whereas a large percentage of infected animals presented cysts in both the liver and lung. Overall, about 26% of parasitized sheep were found to be heavily infected and 12.15% of infected animals harboured fertile cysts. In the second survey, carried out ten years after the first, during the period 2005-2010 in absence of specific control measures, a total of 1414 sheep were examined. CE prevalence was 65%, 78% in the most rural Oristano province and 58% in the most "urbanised" province of Cagliari. Frequency of sheep infected in both the liver and lung had decreased slightly compared to the first survey, particularly in the Cagliari province, as had intensity and mean abundance, though to a lesser extent in the Oristano province. 14.6% of parasitized sheep were heavily infected, showing a general decline over the 10 years between the two surveys, particularly in the Cagliari area where the figure had more than halved. Conversely, about 14% of infected sheep hosted at least 1 fertile cyst, a slight increase compared to the 1st survey. Finally, the trend of CE transmission in Sardinian sheep according to surveys carried out from 1952 to 2010 has been analysed and the results are discussed in the light of the significant socio-economic and structural transformations that have actually modified the zoonosis scenario on the island.

A retrospective analysis of human cystic echinococcosis in Sardinia (Italy), an endemic Mediterranean region, from 2001 to 2005.

To assess the current impact of human CE in Sardinia (Italy) and to monitor the changes over time, a survey has been carried out for the period 2001-2005 using hospital inpatient discharge reports (HDR) as information source, supplementing data wherever possible with additional information retrieved directly from medical records. The total of 726 admissions with "Echinococcosis" as primary diagnosis (annual rate of 8.9 per 100,000 inhabitants) concerned 540 CE cases with an annual mean incidence rate of 6.62 per 100,000 inhabitants. Male-to-female ratio was 1.36, suggesting a marked risk associated with traditional male occupations. Age-specific incidence showed increasing rates of clinical CE with age for both genders. The liver was found to be the most common localization, affecting 72% of patients, while pulmonary CE was more frequent in males than in females. CE risk was unevenly distributed in the island. The more pastoral areas had the highest probability of humans becoming infected, with an incidence rate of clinical cases of approximately 14.0 per 100,000 for areas with sheep/inhabitants index of >6. Compared to the past, incidence rates appear to be decreasing both for pulmonary and hepatic localizations, while there is a reversal of the CE "urbanization" trend resulting in "ruralization", accompanied by a greater degree of parasite ecological "isolation" and focus-points of infection risk. In spite of this decrease, the cost of hospital care alone (approximately 4 million euros) suggests that the monetary plus non-monetary costs of CE are still very high but not fully recognised.

Morphological study of anomalous "laminated" brood capsules in cystic echinococcosis in humans and sheep.

"Anomalous", as yet unreported forms of brood capsules (BC) in cystic echinococcosis larvae from humans and sheep are described, thought to be the likely effect of degenerative involution of the parasite. Morphological examination showed an inner laminated layer (LL) in the brood capsules in intimate contact with the internal wall surface, suggesting the term "laminated brood capsules" (LBC). Analysis conducted on LBC from cysts of different typology invariably revealed them to contain just dead and highly degenerated protoscoleces (PSC). Structural and ultrastructural aspects of these peculiar forms are described and possible processes of formation discussed. Comparison of germinal layer (GL), BC wall and PSC organization recognize a "tegumental" and a "non-tegumental" pole, coinciding in GL and PSC and inverted in BC. A quite reversible PSC-or-LL switch governed by complex mechanisms is proposed, of which PSC viability/death is assumed to be an essential part, that under certain conditions makes in vivo LL production inwards possible in BC.

[Ecographic evaluation of the vitality/fertility in the hepatic hydatidosis as indication for pericistectomy]. / Valutazione ecografica della vitalità/fertilità nell'idatidosi epatica come indicazione alla pericistectomia.

Hepatic hydatidosis is still now a frequently observed pathology and the total pericistectomy, for surgical difficulties, often request a subtotal pericistectomy with complications such as biliary fistula, haemorrhage and subphrenic abscesses. The Authors reconsidered their hepatic hydatidosis cases to evaluate the indication to the surgery that in their opinion, should have to consider first of all the functional state of the cysts. Infact, only the vital and the fertil ones, less frequent even if rarely found, should have indications to the surgery, because more likely complicated. The dead and steril ones, instead being asymptomatic, should go under periodic control, since destined to degeneration and calcification. Are also compared the pre-surgery data with the parasitologic exam, to evaluate ETG reliability to determine the functional state of the cyst. Twenty one cysts out of 76 were operated correctly because vital/fertile and in 19 of these the ultrasound indications were correct (90.5%). 55 didn't have indications to the surgery since dead/steril and for 51 (92.7%) the ultrasound indication was correct. So we can say that morphological ultrasound data permitted a correct surgery indication for 70 cyst's on their functional state (93.4% of total). In this way the post-operative complication were reduced of 5%. The Authors found morphologic and/or functional ultrasound error for 6 cysts (7.9%), and in only 3 cases (3.9%) the error were both morphological and functional Infact we believe that a ultrasound morphologic classification should have a functional corrispective for the surgical indication So only the unilocular and multivescicular cysts, vital and fertil one, should have indication to the surgery. On the contrary the solid ones should have an ultrasound follow up and treated by chemotherapy if necessary.

Development and sexual maturation of Echinococcus granulosus adult worms in the alternative definitive host, Mongolian gerbil (Meriones unguiculatus).

In the present study for the first time an alternative definitive host model has been established for the complete development of Echinococcus granulosus in Meriones unguiculatus (Mongolian gerbils) up to shelled eggs production, as happened in the natural host. Animals treated with methylprednisolone acetate were orally inoculated with approximately 3000 protoscoleces and the development of parasites in the small intestine observed up to 46 days post-infection (p.i.). The cestodes survive, strobilate, mature sexually and complete their development in the intestine up to production of shelled embryonated eggs containing fully formed six-hooked oncospheres, similarly to the natural canid host (stage 7 by Smyth). Shelled eggs are first observed in the rodent/E. granulosus model at 44 days p.i. Somatic growth in gerbils appears to follow a similar trend to dogs, length increasing to over 3mm at 44 days p.i., while, compared to the natural host, organogenesis is observed only to progress at a slower rate in the early developmental stages. Parasite burden was found to vary among non-inbred animals and developmental stages of worms recovered from the same animal differed widely. Worm localisation follows the pattern observed in the natural host, the parasites appearing for the most part distributed in the proximal third of the small intestine. The development of alternative definitive hosts may facilitate research in this field, overcoming legislative impediments that restrict the use of dogs for experimental purposes.